hello everybody,
as I posted here a while ago that summer I met the "sister" of my 1940 special deluxe in germany, Duesseldorf area (there are only 3 original 1940 sp. deluxe known in germany) and could hear the engine is only running on at least 5 cylinders.
Now the owner did pull the cyl. head and found one completely burnt and a half burnt exhaust valve. Before pulling the head he did examine the cylinders by a special camera looking through the spark plug hole and thought to see a hole in the piston.
I told him: "Dont be scared, a burnt valve and a hole in the piston cannot happen at the same time, one damage excludes the other, and listening to the sound and seeing the engine block vent tube while engine was running I am sure it is a burnt valve, trust to my experience and dont worry".
Now the head is pulled and two valves were gone as expected, but:
The engine has the original pistons "dome type" and to his and my big surprise they have a hole on the top. But it is a "closed" hole (funny description), I mean, if you try to blow through the hole or fill some gas into it you see there is no connection to the engine parts under the piston. Everything is tight as it must be to get compression.
So, what is that hole for and why is it there?
I hope he will take photos before reassembling the repaired head. Unfortunately he is in a 500 mls. distance and I have no days off work to drive there and see it with my own eyes.
But the engine had a good compression on the 4 good cylinders before pulling the head, so there is definitly no hole making a loss of compressure.
Just the 2 cylinders with burnt valves were bad.
Had a look insinde my engine to see what is there and found (as expected) flat pistons, because mine has a 1950 block under the original 1940 head. Found out that 1950 was an extremely cold winter in the area where the car was registered that time and I guess, in 1950 it was not more than a 10 year old oldfashioned car and didnt get the needed attention anymore, so the block froze up by missing antifreeze coolant.
Just as information aside...
So, who has an idea about the holes in the pistons of my pals car?
Stefangermany
